Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
As Mount Wilson transitions into September, the average high-temperature stands at a warm 83.8°F (28.8°C), offering little variation from the preceding month. In Mount Wilson, September nights witness a remarkable decline from the day's zenith to an enjoyable 61.9°F (16.6°C).Heat index
For September, the heat index is evaluated at 84.2°F (29°C). Ongoing exposure and activity could lead to a state of exhaustion, with a chance of heat cramps.From a standpoint of the heat index, values pertain to shaded conditions and mild breezes. The direct sunshine could escalate the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', determines the feeling of heat when you account for the relative humidity. The influence of weather is personal, differing among a variety of individuals based on differences in body mass, stature, and the level of physical activity. Consider the fact that direct sun exposure can influence how hot one feels, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical for babies and toddlers. Typically, young kids are at a higher risk than adults since they sweat less. Also, the larger skin surface in proportion to their small bodies and the heightened heat production due to their active nature adds to their vulnerability.
Humidity
In September, the average relative humidity is 47%.Rainfall
In Mount Wilson, in September, it is raining for 3.4 days, with typically 0.2" (5mm) of accumulated precipitation. Throughout the year, there are 50.3 rainfall days, and 8.7" (221mm) of precipitation is accumulated.Snowfall
May through October are months without snowfall in Mount Wilson.Daylight
In Mount Wilson, the average length of the day in September is 12h and 22min.On the first day of the month, sunrise is at 6:26 am and sunset at 7:17 pm. On the last day of September, in Mount Wilson, sunrise is at 6:46 am and sunset at 6:37 pm PDT.
Sunshine
The average sunshine in September in Mount Wilson is 10.8h.UV index
The months with the highest UV index are June through September, with an average maximum UV index of 6. A UV Index of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV radiation for the average person.Note: An average maximum UV index of 6 in September leads to these recommendations:
Avoid overexposure. Fair-skinned individuals can burn in under 20 minutes. Avoid direct Sun exposure from 10 a.m. to 4 p.m., a period when UV radiation is most intense, and remember that not all shade structures provide full protection. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
Frequently asked questions
Is it hot in Mount Wilson during September?
What is the average humidity in September in Mount Wilson?
How many days does it rain in September in Mount Wilson?
When it does not snow in Mount Wilson?
How many hours of daylight does Mount Wilson have in September?
When are sunrise and sunset in September in Mount Wilson?
How many hours of sunshine does Mount Wilson have in September?
What is the month with the highest UV index in Mount Wilson?
What is the UV index reading in September in Mount Wilson?
Average temperature in September
Mount Wilson, CA
- Average high temperature in September: 83.8°F
The warmest month (with the highest average high temperature) is August (86.2°F).
The month with the lowest average high temperature is December (58.5°F).
- Average low temperature in September: 61.9°F
The month with the highest average low temperature is August (64°F).
The coldest month (with the lowest average low temperature) is December (43.3°F).
Average pressure in September
Mount Wilson, CA
- Average pressure in September: 29.89"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
Mount Wilson, CA
- Average wind speed in September: 4.5mph
The windiest month (with the highest average wind speed) is April (6mph).
The calmest month (with the lowest average wind speed) is September (4.5mph).
Average humidity in September
Mount Wilson, CA
- Average humidity in September: 47%
The month with the highest relative humidity is March (56%).
The month with the lowest relative humidity is August (45%).
Average rainfall in September
Mount Wilson, CA
- Average rainfall in September: 0.2"
The wettest month (with the highest rainfall) is February (1.73").
The driest month (with the least rainfall) is June (0.08").
Average rainfall days in September
Mount Wilson, CA
- Average rainfall days in September: 3.4 days
The month with the highest number of rainy days is March (6.4 days).
The month with the least rainy days is June (1.3 days).
Average snowfall in September
Mount Wilson, CA
- Average snowfall in September: 0"
The month with the highest snowfall is December (2.99").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Mount Wilson, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Mount Wilson, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in September: 10h and 5min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The months with the least sunshine are January, February and December (Average sunshine: 6h and 54min).
Average sunshine days in September
Mount Wilson, CA
- Average sunshine days in September: 25.6 days
The month with the most sunshine days is June (27.9 days).
The month with the least sunshine days is February (21.4 days).
Average UV index in September
Mount Wilson, CA
- Average UV index in September: 6
The months with the highest UV index are June, July, August and September (UV index 6).
The months with the lowest UV index are November and December (UV index 3).
Average cloud cover in September
Mount Wilson, CA
- Average cloud cover in September: 7
The months with the most cloud cover are March and December (Cloud cover 22).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in September
Mount Wilson, CA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Mount Wilson, California, USA
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